High speed automatic printing machines used in commercial photoprocessing operations (e.g., machines of the type sold by Eastman Kodak Company under their designation Kodak 2610) print contiguous pictures or print frames on an elongated strip of photographic print paper contained within the machine. Typically, the machine includes means for advancing elongated, spliced-together strips of film negatives through the machine, and also includes means for advancing an elongated strip of photographic print paper through the machine in a step-by-step operation in response to successive paper advance signals generated by the machine, thereby to effect an exposure of successive ones of said negatives onto the photosensitive side of successive portions of the strip of print paper. The photoprinting machine typically includes, moreover, a marking system therein responsive to each of the paper advance signals for placing an identifiable cut mark on the strip of print paper between each pair of adjacent print frames, for later use in cutting individual photographic prints from the elongated strip of photographic print paper following photographic development of the print paper. The photoprinting machine also typically includes means responsive to detection of a splice in said spliced-together strips of film negatives for activating the marking system in the machine to place separately identifiable sort marks on the strip of print paper at appropriately-spaced locations for later use in sorting different customer orders from one another after photographic development of the print paper.
It is important that the photoprinter marking system operate in reliable fashion to place the aforementioned cut marks and sort marks on the strip of print paper. However, since the undeveloped rolls of print paper must be kept in a dark environment until the print paper has been developed, failure of the marking system in the photoprinter cannot be detected visually. If such failure of the marking system occurs, it results in the need for film reprocessing or the expenditure of manual labor to hand-cut the prints from the print paper and/or to separate the various customer orders (i.e., rolls of film) from one another, which adds significant costs as well as production time delays to the overall photoprocessing operation.
The present invention is intended to eliminate these problems.